import com.fasterxml.jackson.databind.ObjectMapper;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet("/authorInfo")
public class AuthorServlet extends HttpServlet {
    private ObjectMapper objectMapper=new ObjectMapper();
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("application/json;charset=utf8");
        //通过这个方法，，获取到指顶博客作者信息
        String param = req.getParameter("blogId");
        if(param == null || "".equals(param)){
            resp.getWriter().write("{\"ok\":false,\"reason\":\"参数缺失\"}");
            return;
        }

        //根据当前的blogId在数据库中查找，找到对应的Blog对象，在进一步的根据blog对象，找到作者信息
        BlogDao blogDao=new BlogDao();
        Blog blog=blogDao.selectOne(Integer.parseInt(param));
        if(blog==null){
            resp.getWriter().write("{\"ok\":false,\"reason\":\"要查询的博客不存在\"}");
            return;
        }

        //根据blog对象，在查询到用户对象
        UserDao userDao=new UserDao();
         User author=userDao.selectById(blog.getUserId());
         if(author == null) {
             resp.getWriter().write("{\"ok\":false,\"reason\":\"要查询的用户不存在\"}");
             return;
         }
         //把author对象返回给浏览器
        //此处不能把密码显示出来
        author.setPassword("");
        resp.getWriter().write(objectMapper.writeValueAsString(author));
    }
}
